The present invention relates to an absorbent pad for meat and poultry products and the like, and to the method for constructing such absorbent pads. More particularly, the present invention relates to a new and improved absorbent pad incorporating superabsorbent granules therein, and to a method for constructing the same.
Meat and poultry food products are typically sold in a supporting tray that is overwrapped by a transparent plastic film or in transparent plastic bags, enabling viewing and inspection of the food products. The public has become accustomed to purchasing meat and poultry food products contained within such packages, not only because the products can be easily viewed and inspected, but also because consumers believe that the food products contained within such packages are maintained in a sterile environment. While it is true that supporting trays with transparent plastic overwrap and transparent plastic bags do, in fact, protect the food products from external contamination, consumers are not always aware of the potential for internal contamination, as the result of juices or liquids exuded from such food products. It has been found that juices or liquids exuded from such food products can support the rapid growth of bacteria which migrate back into and around the food products, resulting in spoilage or deterioration of food products. Furthermore, such exuded liquids or juices create an undesirable visual impression to a consumer, giving the consumer the impression that the food products are unappealing.
As a result, substantial developments have been made in an effort to overcome such problems. In general, these developments have centered around the use of an absorbent pad which is received in a supporting tray or bag and underlies food products in the supporting tray or bag. However, the problem is not so easily solved by providing an absorbent pad alone, because commonly used absorbent pads do not necessarily absorb all of such liquids or juices, and further, the meat or poultry product still come into contact with the juices or liquids absorbed by the absorbent pad. As a result, some absorbent pads have been developed with an imperforate plastic film or non-absorptive barrier above the absorbent pad allowing side and bottom wicking of the exuded liquids and juices, while seeking to prevent reverse migration of the liquids or juices back into contact with the food products. An example of this is shown in U.S. Pat. No. 3,026,209. Some more recent developments have included the use of an absorbent pad sealed within upper and lower plastic films, and with one of the upper or lower films being perforated for top and/or bottom wicking of the exuded liquids or juices by the absorbent pad within the sealed upper and lower film layers. Examples of circumferential and peripherally sealed upper and lower plastic films containing an absorbent pad therein are shown by U.S. Pat. Nos. 4,275,811; 4,321,997; 4,382,507 and 4,410,578. In general, these patents teach that perforating only one film layer, preferably the bottom film layer only, permits bottom wicking and retention of the exuded liquids or juices within the circumferentially sealed upper and lower film layers, without any reverse migration of the liquids or juices back into the food products.
While the aforementioned designs have worked quite well for their intended purposes, they have not solved all of the problems associated with exuded liquids or juices from meat and poultry products. Thus, where the bottom plastic film is perforated to allow for bottom wicking only, some liquids or juices remained trapped between the imperforate upper film layer and the food product, creating the potential for spoilage or discoloration. Even where both the upper and lower plastic film layers have been perforated to allow for both top and bottom wicking, the absorbent layer has not been sufficiently absorbent to retain the liquids or juices therein. Some of the prior art designs have even suggested various additives to the absorbent pad to increase its absorbency; however, in fact, none of the proposed additives have functioned well enough to absorb and retain the exuded liquids or juices within the absorbent pad. Where the absorbent pad has reached its maximum potential absorbency, no more liquids or juices can be absorbed, and this results in excess juices remaining outside of the absorbent pad for contact with the meat products and/or viewing by the consumer.
It has been observed that the absorbent pad, according to the U.S. Pat. Nos. 4,275,811, 4,321,997, 4,382,507 and 4,410,578, cannot sufficiently absorb and retain the juices from the meat products in certain applications. For example, if the absorbent pad is exposed to pressure, the juice will be squeezed out from the pad and onto the product. In U.S. Pat. No. 4,321,997, the absorbent pad is provided with a spacing means for preventing the squeezing out of the juices, recognizing that such problem exists.
According to the present invention, it has been observed that the inclusion of a superabsorbent material in the absorbent pad improves the retention properties of the absorbent pad so that it does not give off the absorbed liquid even when exposed to a pressure. Due to this property, it is now possible to enclose the absorbent pad within plastic sheets wherein the upper sheet is perforated. Thus, the risk that the juice is accumulated between the meat product and the upper sheet is avoided.
However, it is very important that the superabsorbent particles are evenly spaced within the absorbent pad and retained in place. According to the present invention, this object is achieved by including the superabsorbent particles in a network formed between cellulosic fibers and thermoplastic fibers (or other similar fibers), which are bonded in a thermobonding process. The superabsorbent particles are generally homogeneously dispersed or evenly spaced in the material and held in place by the interacting thermoplastic and cellulosic fibers. Thus, the superabsorbent particles, when absorbing liquid, are prevented from moving within the material. It is believed that this property is sufficient for preventing reverse migration of the juices back to the meat product, even when the upper sheet is perforated. In applications where higher demands are placed on the absorbent pad, it may be constructed with an imperforate upper sheet, but the sides thereof may still be unsealed so that the juices are absorbed through said sides.